build(deps-dev): bump @eslint/js from 9.20.0 to 9.21.0

Bumps [@eslint/js](https://github.com/eslint/eslint/tree/HEAD/packages/js) from 9.20.0 to 9.21.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/main/CHANGELOG.md)
- [Commits](https://github.com/eslint/eslint/commits/v9.21.0/packages/js)

---
updated-dependencies:
- dependency-name: "@eslint/js"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Diff for: package-lock.json

@@ -50,7 +50,7 @@
   },
   "devDependencies": {
     "@eslint/eslintrc": "^3.1.0",
-    "@eslint/js": "^9.20.0",
+    "@eslint/js": "^9.21.0",
     "@koa/cors": "^5.0.0",
     "@koa/ejs": "^5.1.0",
     "@types/express": "^5.0.0",